Hydroisomerization of Benzene-Containing Gasoline Fractions
on a Pt/SZrO₂Al₂O₃ Catalyst:
II. Effect of Chemical Composition on Acidic and Hydrogenating
and the Occurrence of Model Isomerization Reactions

M. O. Kazakov^a, A. V. Lavrenov^a, I. G. Danilova^b, O. B. Belskaya^a, and V. K. Duplyakin^a

^a Institute of Hydrocarbons Processing, Siberian Branch, Russian Academy of Sciences, Omsk, 644040 Russia

^b Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090 Russia

e-mail: max@ihcp.oscsbras.ru

Received March 23, 2010

Abstract—The acidic and hydrogenating of –ZrO₂–Al₂O₃ samples containing from 18.8 to 67.8 wt %
Al₂O₃ as a support constituent were studied by the IR spectroscopy of adsorbed CO and pyridine, and the model
reactions of n-heptane and cyclohexane isomerization on these catalysts were examined. The total catalyst
activity in the conversion of n-heptane decreased with the concentration of Al₂O₃; this manifested itself in an
increase in the temperature of 50% n-heptane conversion from 112 to 266C and in an increase in the selectivity of
isomerization to 94.2%. In this case, the maximum yield of isoheptanes was 47.1 wt %, which was reached on a
sample whose support contained 67.8 wt % Al₂O₃. A maximum yield (69.6 wt %) and selectivity (93.7%) for
methylcyclopentane formation from cyclohexane were also reached on the above catalyst sample. This can be
explained by lower concentrations of Lewis and Brønsted acid sites in the –ZrO₂–Al₂O₃ system, as
compared with those in –ZrO₂. The experimental results allowed us to make a preliminary conclusion
that the –ZrO₂–Al₂O₃ catalyst whose support contains 67.8 wt % Al₂O₃ is promising for use in the
selective hydroisomerization of benzene-containing gasoline fractions in the thermodynamically favorable pro-
cess temperature range of 250–300C.

DOI: 10.1134/S0023158411040057

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